France have made it four wins out of four and a maximum 20 points with their reserve side defeating the United States 41-14 in a free-flowing Rugby World Cup pool B game in Wollongong.

It was further confirmation that the 2002 Six Nations Grand Slam champions have impressive strength-in-depth and sets them up nicely for the knock-out stages, starting with a quarter-final against either Australia or Ireland.

The French scored five tries, with a hat-trick going to centre Brian Liebenberg.

The Americans, losing their third game out of four, departed the competition with honour, scoring two converted second-half tries.

France took the lead after four minutes, when the Americans were caught offside as the French pack drove forward and Merceron made no mistake from the ensuing penalty.

Merceron made it 6-0 with the boot six minutes later when the American props went offside as France launched an attack, after US fullback John Buchholz had fumbled a long Damien Traille clearing kick into touch in his own half.

The Americans, knowing they were on their way home no matter what the result, mixed it up to effect, but basic errors let them down in the gusting wind.

They gave away another needless penalty on attack and were made to pay when French full-back Clement Poitrenaud launched into a mazy run that spread-eagled the Americans before he was brought down.

On the ensuing phase, Merceron fed out to the South-African born Liebenberg to dive over for the try in 14 minutes which Merceron failed to convert.

Liebenberg, seeing his first action of the World Cup, doubled up four minutes later, finishing off a move which saw Merceron feed the back-row pair of Sebastien Chabal and Christian Labit, who fixed the US defence under the posts.

France were firmly in command and were unlucky not to add to their total when Yachvili touched down in the corner, only for his effort to be ruled out for inching a foot out of play.

But the third try duly came six minutes from the break when the French pack drove forward from a scrum and muscled over prop forward Jean-Baptiste Poux.

Merceron rounded off the half with a penalty from under the posts to make it 26-0.

The Americans cut the leeway with a converted try three minutes into the second half when they broke clear into the French 22 metres and were awarded a penalty a yard out from the line.

They elected to run and flanker Kort Schubert went over, flyhalf Mike Hercus converting.

That opened up play and three more tries followed in the next 11 minutes.

Liebenberg grabbed his hat-trick after 48 minutes, but the Americans were not finished as they pinned the French back on their own line and Hercus squeezed in past the cover three minutes later.

But on the next play, France scored their fifth and last try through hooker and skipper for the day Yannick Bru.